Speed control for electronic organ rotating horn

ABSTRACT

In an electronic organ having a loudspeaker mounted for rotation about an axis inclined to the axis of the loudspeaker, a manual control controls the speed of the motor rotating the loudspeaker continuously between upper and lower adjustable limits, which limits are set independently. When the manual control is adjusted to select the lower speed limit, an oscillator controlling a circuit for inducing vibrato or &#39;&#39;&#39;&#39;electronic rotation&#39;&#39;&#39;&#39; is caused to generate a predetermined frequency.

United States Patent [191 Wilder 1 Feb. 4, 1975 1 SPEED CONTROL FOR ELECTRONIC 3,571,681 3/1971 Burns 318/231 ORGAN ROTATING HORN 3,588,743 6/1971 Fjallbrant 331/137 [76] Inventor: Dallas Richard Wilder, 715 N.

Kedzie Ave., Chicago, lll. 60612 [22] Filed: Oct. 2, 1972 [21] App]. No.: 294,024

[52] U.S. Cl. 179/1 .1. 84/125 [51] Int. Cl 1102 5/34, GOlh 1/02 [58] Field of Search 179/1 J; 84/1.24, 1.25, 84/126; 318/231; 331/137 [56] References Cited UNITED STATES PATENTS 2,622,692 12/1952 Leslie 179/1 .1

2,995,054 8/1961 Leslie 179/1 .1

3,183,453 5/1965 Amlinger 33l/l37 3,266,592 8/1966 Leslie 179/1 J.

3,520,559 7/1970 Ross 179/1 .1

3,594,623 7/1971 Lamaster..'. 318/231 Primary Examiner-William C. Cooper Attorney, Agent, or Firm--Hill, Gross, Simpson, Van Santen, Steadman, Chiara & Simpson ABSTRACT ln an electronic organ having a loudspeaker mounted- 8 Claims,2 Drawing Figures PATENTED FEB' 4 5 I sum 1 M 2 PAIENTEU FEB 41975 SHEET 2 OF 2 SPEED CONTROL FOR ELECTRONIC ORGAN ROTATING HORN BACKGROUND OF THE INVENTION The present invention relates to electronic organs and, in particular, to a rotating loudspeaker therefore for effecting mechanical modulation of the signal produced by the loudspeaker.

The mechanical modulation produces a distinctive effect, which is sometimes used in combination with other effects produced electronically, such as vibrato, or the like. In mechanical modulation, a loudspeaker or horn is mounted for rotation about an axis approximately at right angles with the axis of the horn or loudspeaker, so the the amplitude of the sound produced by the horn, from the standpoint of an observer, appears to increase and decrease as the horn is rotated. Markedly different effects are produced with the different speeds of rotation of the horn, and it is accordingly desirable to provide means for manually adjusting the speed of rotation of the horn.

It is also desirable to establish upper and lower limits for the range of manual control so that movement of 'the manual control actuator to either ofits extreme positions produces a preselected speed of rotation.

It is also desirable to interrelate the operation of the mechanical modulation system with an electronic system adapted for supplying vibrato. Such an electronic system is desclosed in Wilder US. Pat. No. 3,4l8,4l8, issued Dec. 24, 1968.

SUMMARY OF THE INVENTION Accordingly, it is a principal object of the present invention to provide means for manually adjusting the speed of the motor rotating the horn.

Another object of the present invention is to provide means for independently adjusting the range of speed control effected by the manually operated control unit so that a preselected maximum rotation speed is chosen, and a preselected minimum speed is chosen, with continuous control between the two limits.

A further object of the present invention is to provide apparatus for automatically selecting a lower frequency of operation for the electronic vibrato when the minimum speed horn rotation speed is selected.

These and other objects of the present invention will become manifest upon an examination ofthe following description and the accompanying drawing.

In one embodiment of the present invention, there is provided a variable frequency oscillator and an amplifier, interconnected between the oscillator and an ac. motor provided for rotating the horn. The frequency of the oscillator is adjustable by manually adjusting a variable resistor connected in circuit therewith, with separate variable resistors being provided for independently selecting the maximum and minimum frequencies of the oscillator. An interconnection between one of the variable resistors and an oscillator for driving an electronic rotation unit is also provided to cause a preselected frequency to be generated by the oscillator, when the lowest speed is selected.

BRIEF DESCRIPTION OF THE DRAWINGS Reference will now be made to the accompanying drawings, which taken together comprise a schematic circuit diagram illustrating an exemplary embodiment of the present invention.

FIG. 1 is a schematic circuit diagram of the variable frequency oscillator for-the loudspeaker; and

FIG. 2 is a schematic circuit diagram of the manually operable controlv for the oscillator of FIG. 1, and of a variable frequency oscillator for the vibrator or electonic rotation unit.

DESCRIPTION OF THE INVENTION Referring now to FIG. I, the horn or loudspeaker is supported by a support member 12, which is coupled for rotation to a motor 14. An electro-acoustical transducer or driver 16 is associated with the support member 12, and the open end 18 of the driver 16 is coupled with an interior chamber 20 within the member 12, so that the acoustical energy produced by the'driver I6 is conducted to the end of the horn l0. Energizing terminals 22 and 24 of the driver 16 are connected respectively through a capacitor 26 to a jack 28, and toground via line 30. The output of the power amplifier (not shown) of the organ is connected to the jack 28, via a cable 108 and another jack 2 (FIG. 2.)

The power for the motor 14 is delivered from a variable frequency oscillator 32, the output of which is amplified by an amplifier 34. The oscillator 32 employsa transistor 35 having its collector connected through a resistor 36 to a source of positive voltage at a terminal 38. The emitter of the transistor 35 is connected to ground through a parallel circuit including a resistor 40 and a capacitor 42. The collector of the transistor 35 is also connected to its base by means of a three-step phase shifting circuit. The first step includes a capacitor 44 and a resistor 46 connected in series from the collector of the transistor 35 to ground. The second step includes, connected in parallel with the resistor 46, a series connected capacitor 48 and two resistors 50 and 52. The third step includes a capacitor 54 connected to the base of the transistor 35 from the junction between the capacitor 48 and the resistor 50. A resistor 56 is connected from the "base of the transistor 35 to ground. Bias is supplied to the transistor 35 through a resistor 58 connected from a terminal 38 to its base.

The three-step phase shifting circuit shifts the phase of the signal present at the collector by 180, and presents it to the base. The frequency at which the phasev shift is 180 depends upon the'effective resistance of the circuit including the resistors 50 and 52, which is controlled manually by means of the manual speed control 60 (FIG. 2), the operation of which will be described more fully hereinafter.

The signal produced by the oscillator 32 is amplified by a circuit including transistors 62 and 64. The collector of the transistor 64 is connected to the base of the transistor 62 by means of a capacitor 66 and a resistor 68. Bias is supplied to the base of the transistor 62 by a resistor 70 connected to the terminal 38.

The emitter of the transistor 62 is connected directly to the base of the transistor 64, and to ground through a resistor 72. The collectors of transistors 62 and 64 are connected in common through the primary ofa transformer 74 and through a resistor 76 to the terminal 38. The transistor 64 is biased by a resistor 78 connected from its emitter to ground, and a resistor 80 connected from the emitter to the junction of the resistor 76 and the primary of the transformer74.

The transformer 74 has two balanced secondary windings, each of which is connected to drive a separate transistor. One secondary winding 82 hasone terminal connected to the highest tap of a voltage divider including resistors 84, 86, 88 and 90 connected in series across a source of positive voltage extending between terminals 92 and 94. The other terminal of the winding 82 is connected to the base of a transistor 96. The other secondary winding 98 is connected between the lowest tap of the voltage divider and the base of a transistor 100. The collector of the transistor 96 is connected to the terminal 92, and its emitter is connected to the collector of the transistor 100 and to an intermediate tap of the voltage divider. The emitter of the transistor 100 is connected to the terminal 94. The motor 14 is connected between the intermediate tap of the voltage divider and the terminal 94, through a capacitor 102.

The variable speed control unit 60 (FIG. 2) is connected to the junction of the resistors 50 and 52 (FIG. 1) through a series of jacks and connectors, which facilitate installation of the equipment, and, if necessary, disassembly. The junction between the two resistors 50 and 52 is connected by a line 104 to the outer contact 106 of the jack 28, which is connectable by means of a cable 108 to the outer contact 110 of a jack 112. A lead 114 connects thiscontact with the outer contact 116.0fa jack 118, and a further cable 120 connects the outer contact of the jack 118 with the outer contact 122 of a jack 124. The cables 108 and 120 have plugs attached to their ends for selectively completing the circuit which has been described.

The speed control unit 60 has a main control potentiometer 126 with two associated rheostats 128 and 130. The rheostats 128 and 130 are provided for the purpose of adjusting the upper and lower limits, respectively, ofthe frequency of the variable frequency oscillator 32. The contact 122 is connected in series through the rheostats 128 and 130 to ground, the ground connection being established by means of a contact 132 on the jack 124. All of the jacks which have been mentioned above have similar ground contacts which are interconnected by the cables 108 and 120.

The main control potentiometer 126 has its tap connected to ground so that operation of the potentiometer 126 changes the amount of resistance in parallel with the low limit rheostat 128. When the potentiometer 126 is adjusted so that the low limit rehostat 128 is effectively short circuited, the high level rheostat is made effective to control the minimum amount of resistance placed in parallel with the resistor 52. When the potentiometer 126 is at its other extreme, however, the low limit rheostat 128 is effective to determine the maximum amount of resistance placed in parallel with the resistor 52. ln this condition, the high limit rheostat 130 is substantially ineffective because the resistance of the high limit rheostat 130 is much less than that of the low limit rheostat 128. Accordingly, the limit frequencies which are set by the limit rheostats 128 and 130 are in each case substantially independent of the operation of the other. Once the upper and lower limits are set, by manually adjusting the position of the taps of the rheostats 128 and 130, the operator may choose either selected frequency by simply moving the actuator of the potentiometer 126 to either of its two extreme positions.

The taper of the potentiometer 126 is preferably great enough so that the speed of rotation of the motor 14 is approximately proportional to movement of the tance of the potentiometer 126 is approximately K ohms, the potentiometer 126 has about 6 K ohms to 9 K ohms of its total in the right half of the potentiometer, as shown in FIG. 2, and the remainder in the left half.

The inner contact 134 of the jack 124 is connected by means of the cable 120 to the inner contact 136 of the jack 118, and from there over a line 138 to the base of a switching transistor 140. Operation of the transistor 140 selects a low frequency for a vibrato or electronic rotation" system, which system is described in the aforementioned Wilder Patent. The electronic rotation unit employs an oscillator 142 having a pair of transistors 144 and 146. The transistor 144 has its collector connected to a source of positive voltage at a terminal 147, through a resistor 148, and its emitter is connected to ground through a resistor 150. The collector of the transistor 144 is connected to the base of the transistor 146 via a line 152. The collector of the transistor 146 is connected to the terminal 147 via a resistor 154. The emitter of the transistor 146 is connected to ground viaya resistor 156. The emitter of the transistor l46is also connected by means of a two-step shifting circuit to the base of the transistor 144. The first step includes a series-connected capacitor 158 and resistor 160, extending between the emitter of the transistor 146 and ground. The second step includes a capacitor 162 connected between the junction of the capacitor 158 and resistor to the base of the transistor 144. The base of the transistor 144 is connected to ground by a resistor 164 and to the terminal 147 by a resistor 166.

The circuit including the transistors 144 and 146 functions as an oscillator, the frequency of which is determined by the components of the phase shifting circuit. The output of the oscillator is made available at the tap of a potentiometer 168 connected between the emitter of the transistor 146 and ground, which potenconnected to ground through a resistor 176. It is biased.

by a resistor 178connected from its base to the terminal 147, and a resistor 180 connected from its base to ground. The emitter of the transistor is connected via a line 182 to the base of the transistor 172, the emitter of which is connected to ground through a resistor 184. Its collector is connected to the terminal 147 through a circuit including a resistor 186, the lamp 174, a panel indicator lamp 188 and a switch 190, which is provided for selectively disabling the electronic rotation function when desired. The range or amplitude of the phase modulation effected by the electronic rotation is controlled by the adjustment of the potentiometer 168.

lt is desirable for the oscillator 142 to generate a lower frequency when the frequency applied to the motor 14 is near its minimum. To accomplish this is the function of the switching transistor 140, the base of which, as already described, is connected through the cable 120 and the inner contact 134, of the jack 124 to one end of the main control variable resistor 126. The collector of the transistor 140 is connected to the junction of the capacitor 158 and the resistor 160, and its emitter is connected to ground through a resistor 191 and a rheostat 192. A resistor 194, connected between the base of the transistor 140 and the terminal 147, provides bias to the transistor 140 to maintain it normally conducting so that the circuit including the rheostat 192 and the resistor 191 is normally in parallel with the resistor 160. By means of the rheostat 192, the frequency of the oscillator 142 may be adjusted as desired. The resistor 191 establishes a minimum value for the resistance which is placed in parallel with the resistor 160. When the variable resistor 126 is adjusted so that the tap is near the end associated with the lowest frequency of horn rotation, the voltage on the base of the transistor 140 is lowered considerably by virtue of the low resistance through part of the variable resistor 126 from the base of the transistor 140 to ground. Accordingly, the transistor 140, under these circumstances, is cut off and the full value of the resistor 160 is established in the first leg of the phase shifting circuit of the oscillator 142. This establishes a predetermined minimum frequency for the oscillator 142. The value of the resistor 160 is chosen to produce the desired frequency when the horn rotation speed is minimum.

The energizing terminal 22 of the driver 16 (FIG. 1) is connected to the output of the main power amplifier (not shown) at terminal 196 (HO. 2) through the inner contact 198 of the jack 28, the cable 108, and the inner contact 200 of the jack 112.

Although the various components illustrated in the drawing are intended to function when mutually interconnected by the cables 108 and 120, an inadvertant disconnection of the cables while the system is operating does not produce any damage to the system components. For example, the resistor 52 has a value which is sufficiently small to permit the oscillator 32 to continue oscillating even if the connection established by the cable 108 is interrupted, although this will, of course, deenergize the driver 16. If the connection established by the cable 120 is interrupted, the oscillator 32 will operate in the same manner as if the cable 108 was interrupted, but the driver 16 will continue to be energized normally, provided the connection established by the cable 108 is still in tact. Operation of the transistor 140 is disabled by disconnection of the cable 120, but under these conditions the speed of the motor 114 is at a maximum and the transistor 140 is, accordingly, nonfunctional.

From the foregoing, it is apparent that the present invention performs the functions of establishing the manual control for adjusting the speed of rotation of a rotatable horn, and for establishing upper and lower limits for such speed. in addition, the frequency of the electronic rotation unit is automatically chosen to be a preselected frequency when the lowest speed of rotation of the horn motor is chosen.

In one preferred embodiment, the values of some of the components are as follows:

48 0.2 mfd 50 2 K ohms 52 150 K ohms 126 125 K ohms -Continued l28 available from Is to 50 k ohms 130 available from O to 3.| K ohms I58 4.0 mfd 160 I4 K ohms 5 l9] 2l ohms l92 0 to ohms What is claimed is:

1. For use with an organ amplifier having a loudspeaker with a stationary transducer and a horn mounted at an angle relative to the axis of said transucer for rotation about the axis of said transducer, the combination comprising a single phase a.c. motor for driving said horn, a variable frequency oscillator for generating electrical a.c. power at a variable frequency, means for applying said a.c. power to said motor, and means for manually controlling the frequency of oscillation of said oscillator, said last named means including first variable resistance means for continuously controlling the speed of said motor between upper and lower limits, upper limit variable resistance means for selecting an upper limit for the frequency controlled by said manual control, and lower limit variable resistance means for selecting a lower limit for the frequency controlled by said manual control, said upper and lower limit variable resistance means selecting their respective limits substantially independently, whereby a change in one of said limits has substantially no effect on the other of said limits, and wherein said upper and lower limit variable resistance means comprises first and second variable resistors connected in parallel with each other, and a third variable resistor connected between said variable frequency oscillator and a common terminal of said first and second variable resistors, the

' maximum resistance of said third variable resistor being substantially lower in resistance than said first and second variable resistors.

2. For use with an organ amplifier having a loudspeaker with av stationary transducer and a horn mounted at an angle relative to the axis of said transducer for rotation about the axis of said transducer, the combination comprising a single phase a.c. motor for driving said horn, a variable frequency oscillator for generating electrical a.c. power at a variable frequency,

means for manually controlling the frequency of oscillower limits, upper limit variable resistance means for selecting an upper limit for the frequency controlled by said manual control, and lower limit variable resistance means for selecting a lower limit for the frequency controlled by said manual control, said upper and lower limit variable resistance means selecting their respective limits substantially independently, whereby a change in one of said limits has substantially no effect on the other of said limits, and wherein said oscillator comprises a phase shift oscillator having feedback means for establishing a phase shift in the positive feedback of said oscillator, said feedback means including at least one fixed resistance means, said first variable resistance means being selectively connectable in parallel with said fixed resistance means.

3. Apparatus according to claim 2 wherein said oscillator is a phase shift oscillator having a plurality of resistance-capacitance circuits for shifting the phase of said feedback, and means for connecting said first varimeans for applying said a.c. power to said motor, and.

able resistor in parallel with a resistor of one of said resistance-capacitance circuits.

4. Apparatus according to claim 2 including a cable for selectively interconnecting said oscillator and said manual control means, whereby said variable resistance means may be located remotely from said oscillator and selectively disconnected therefrom.

5. For use with an organ amplifier having a loudspeaker with a stationary transducer and a horn mounted at an angle relative to the axis of said transducer for rotation about the axis of said transducer, the

combination comprising a single phase a.c. motor for driving said horn, a variable frequency oscillator for generating electrical a.c. power at a variable frequency, means for applying said a.c. power to said motor, and means for manually controlling the frequency of oscil- -lation of said oscillator, said last named means including first variable resistance means for continuously controlling the speed of said motor between upper and lower limits, upper limit variable resistance means for selecting an upper limit for the frequency controlled by said manual control, and lower limit variable resistance means for selecting a lower limit for the frequency controlled by said manual control, said upper and lower limit variable resistance means selecting their respective limits substantially independently, whereby a change in one of said limits has substantially no effect quency a.c. signal, means for applying said a.c. signal to said motor, means for manually controlling the frequency of oscillation of said oscillator, said last named means including first variable resistance means for continuously controlling the speed of said motor between upper and lower limits, upper limit variable resistance means for selecting an upper limit for the frequency controlled by said manual control, and lower limit variable resistance means for selecting a lower limit for the frequency controlled by said manual control, and a second oscillator for producing an a.c. vibrato signal for use with a system connected with said loudspeaker. said second oscillator being adjustable in frequency, and means interconnecting said second oscillator and said manual control means for automatically establish-- ing a predetermined frequency for said second oscillator when said manual control means is adjusted so as to select one of said limits for the frequency of said first oscillator.

7. Apparatus according to claim 6 wherein said second oscillator includes a plurality of feedback phase shifting circuits, at least one said phase shifting circuit including resistance means, and means connected with said first variable resistance means to select a predetermined maximum resistance for said one phase-shifting circuit when said manual control means is adjusted so as to select said one limit.

8. Apparatus according to claim 7 including a switching transistor for selectively connecting a variable resis' tance in parallel. with the resistance means of said one phase-shifting circuit, saturating said transistor, and means associated with said first variable resistance means for selectively cutting off said switching transistor when said low limit is selected by said manual control means. 

1. For use with an organ amplifier having a loudspeaker with a stationary transducer and a horn mounted at an angle relative to the axis of said transucer for rotation about the axis of said transducer, the combination comprising a single phase a.c. motor for driving said horn, a variable frequency oscillator for generating electrical a.c. power at a variable frequency, means for applying said a.c. power to said motor, and means for manually controlling the frequency of oscillation of said oscillator, said last named means including first variable resistance means for continuously controlling the speed of said motor between upper and lower limits, upper limit variable resistance means for selecting an upper limit for the frequency controlled by said manual control, and lower limit variable resistance means for selecting a lower limit for the frequency controlled by said manual control, said upper and lower limit variable resistance means selecting their respective limits substantially independently, whereby a change in one of said limits has substantially no effect on the other of said limits, and wherein said upper and lower limit variable resistance means comprises first and second variable resistors connected in parallel with each other, and a third variable resistor connected between said variable frequency oscillator and a common terminal of said first and second variable resistors, the maximum resistance of said third variable resistor being substantially lower in resistance than said first and second variable resistors. Pg,14
 2. For use with an organ amplifier having a loudspeaker with a stationary transducer and a horn mounted at an angle relative to the axis of said transducer for rotation about the axis of said transducer, the combination comprising a single phase a.c. motor for driving said horn, a variable frequency oscillator for generating electrical a.c. power at a variable frequency, means for applying said a.c. power to said motor, and means for manually controlling the frequency of oscillation of said oscillator, said last named means including first variable resistance means for continuously controlling the speed of said motor between upper and lower limits, upper limit variable resistance means for selecting an upper limit for the frequency controlled by said manual control, and lower limit variable resistance means for selecting a lower limit for the frequency controlled by said manual control, said upper and lower limit variable resistance means selecting their respective limits substantially independently, whereby a change in one of said limits has substantially no effect on the other of said limits, and wherein said oscillator comprises a phase shift oscillator having feedback means for establishing a phase shift in the positive feedback of said oscillator, said feedback means including at least one fixed resistance means, said first variable resistance means being selectively connectable in parallel with said fixed resistance means.
 3. Apparatus according to claim 2 wherein said oscillator is a phase shift oscillator having a plurality of resistance-capacitance circuits for shifting the phase of said feedback, and means for connecting said first variable resistor in parallel with a resistor of one of said resistance-capacitance circuits.
 4. Apparatus according to claim 2 including a cable for selectively interconnecting said oscillator and said manual control means, whereby said variable resistance means may be located remotely from said oscillator and selectively disconnected therefrom.
 5. For use with an organ amplifier having a loudspeaker with a stationary transducer and a horn mounted at an angle relative to the axis of said transducer for rotation about the axis of said transducer, the combination comprising a single phase a.c. motor for driving said horn, a variable frequency oscillator for generating electrical a.c. power at a variable frequency, means for applying said a.c. power to said motor, and means for manually controlling the frequency of oscillation of said oscillator, said last named means including first variable resistance means for continuously controlling the speed of said motor between upper and lower limits, upper limit variable resistance means for selecting an upper limit for the frequency controlled by said manual control, and lower limit variable resistance means for selecting a lower limit for the frequency controlled by said manual control, said upper and lower limit variable resistance means selecting their respective limits substantially independently, whereby a change in one of said limits has substantially no effect on the other of said limits, and wherein said upper limit and lower limit variable resistance means are connected in series, and said first variable resistance means is connected in parallel with one of said other variable resistance means.
 6. For use with an organ amplifier having, a loudspeaker having a horn mounted for rotation by a motor about an axis forming an angle with the axis of said loudspeaker, the combination comprising a variable frequency oscillator for generating a variable frequency a.c. signal, means for applying said a.c. signal to said motor, means for manually controlling the frequency of oscillation of said oscillator, said last named means including first variable resistance means for continuously controlling the speed of said motor between upper and lower limits, upper limit variable resistance means for selecting an upper limit for the frequency controlled by said manual control, and loweR limit variable resistance means for selecting a lower limit for the frequency controlled by said manual control, and a second oscillator for producing an a.c. vibrato signal for use with a system connected with said loudspeaker, said second oscillator being adjustable in frequency, and means interconnecting said second oscillator and said manual control means for automatically establishing a predetermined frequency for said second oscillator when said manual control means is adjusted so as to select one of said limits for the frequency of said first oscillator.
 7. Apparatus according to claim 6 wherein said second oscillator includes a plurality of feedback phase shifting circuits, at least one said phase shifting circuit including resistance means, and means connected with said first variable resistance means to select a predetermined maximum resistance for said one phase-shifting circuit when said manual control means is adjusted so as to select said one limit.
 8. Apparatus according to claim 7 including a switching transistor for selectively connecting a variable resistance in parallel with the resistance means of said one phase-shifting circuit, saturating said transistor, and means associated with said first variable resistance means for selectively cutting off said switching transistor when said low limit is selected by said manual control means. 